A Level Computer Science 9618 Paper 31, May/June 2026

set

class / object

A user-defined data type that is used to reference a memory location

MP1 TYPE Word

MP2 = ^STRING

Booking systems e.g. airline / Operating system file management systems / Video games / Encryption utilities / Compression utilities

MP1 Records are stored in no particular order / any available position

MP2 A record key is used to determine the location where the record is to be stored

MP3 … which is generated using a hash function on the key field

MP4 New records are added in an empty location

MP1 Direct file access is used

MP2 A hashing function is used on the key field to find the location in the file where the record is stored

MP3 If the required record is found at the hashed location it is retrieved

MP4 If the required record is not found, a collision resolution strategy is employed // Records from that point are searched linearly until the required record is found // Linear probing

MP1 correct method to find the binary number

MP2 correct use of exponent

MP3 correct answer in the space provided

correct application of exponent seen

correct method to find the final answer

Denary value: −94.25 // −94 1/4

Application: contains all the programs that exchange data and includes protocols: HTTP, FTP and POP3

Transport: ensures packets arrive in sequence without errors

Internet: identifies the intended network and host.

Link: interconnects nodes or hosts in a network, encapsulates IP packets into frames and ensures correct protocols are followed

MP1 Virtual machines can provide an instruction set architecture that is different to the actual computer. // Multiple operating system environments can be used on the same computer. // You can run an application / legacy software which is not compatible with the host computer / operating system using a guest operating system that is compatible with the application / software.

MP2 Costs can be saved by not having to purchase additional hardware to test / use applications.

MP3 The guest operating system can crash without affecting the host machine. // Guest operating system hosted on a virtual machine can be used without impacting anything outside the virtual machine. // When trying a piece of suspicious software, if it causes a problem, it will only infect the virtual machine.

MP4 Degraded performance. // A virtual machine is less efficient than real machines because they access hardware indirectly. // The virtual machine has to request access to the hardware from the host, which slows usability. // If multiple virtual machines are running on the same host, performance may be negatively affected if the host lacks sufficient power to deal with all their requirements.

MP5 A virtual machine is dependent on the features / standard of the host machine. // It may be affected by the weaknesses of the host machine // Not all hardware/software can be emulated.

MP6 Managing and maintaining a virtual machine can be quite complex /specialised.

One mark for columns P, Q and R

One mark for column S

One mark for column Z

Solving logic expressions using a K-map makes it easier because you don’t need to use Boolean algebra. // It is guaranteed to give you an optimal solution. // Converts complex logic problems into simpler ones.

Loop for CD=11 (row of 1s: (00,11), (01,11), (11,11), (10,11))

Loop for AB=11 (column of 1s: (11,00), (11,01), (11,11), (11,10))

2x2 loop for (01,01), (11,01), (01,11), (11,11)

MP1 One correct Boolean term with an OR (+) sign

MP2 All three correct Boolean terms connected by OR signs and no other terms present.

MP1 21 15 3 –

MP2 8 + * 7 /

MP1 (c + d)

MP2 (a - b) * (a - c)

MP3 /( MP2 )

Ring 1 (stacks 1 to 3: 15, then 15 & 9, then 6)

Ring 2 (stacks 4 to 6: 6 & 24, then 6 & 24 & 3, then 6 & 8)

Ring 3 (stacks 7 to 10: 48, then 48 & 18, then 48 & 18 & 6, then 48 & 24)

One mark for the interim total (48) and the final total (2).

Text encrypted from plain text using an encryption algorithm // The result of putting plain text through an encryption algorithm.

A cryptographic/encryption key that can be obtained/used by anyone to send encrypted messages. // A key that is part of a matched pair // An encryption key known to all users // A decryption key obtained/used by anyone to decrypt sender’s digital signature

MP1 The organisation generates a matched pair of encryption keys / MP6 The individual generates a matched pair of encryption keys

MP2 The organisation makes its public key available to the individual / MP7 The individual sends their public key to the organisation

MP3 The individual uses the public key to encrypt their message / MP8 The individual uses their private key to encrypt their message

MP4/MP9 … and sends this message to the organisation / MP5 The organisation decrypts the message using their private key / MP10 The organisation decrypts the message using the individual’s public key

MP1 Supervised learning makes use of labelled training data

MP2 … to predict future events based on past outcomes

MP3 Unsupervised learning makes use of unlabelled training data / training data without instructions on what to do with it / does not use training data with the correct/expected outcomes

MP4 … to search for hidden patterns/relationships/structures/similarities/ outliers within the data

MP5 … to therefore get closer to the desired outcome as the training progresses.

Working MP1 / MP2 / MP3 / MP4 / MP5 / MP6 (Max 3)

Working MP1 / MP2 / MP3 / MP4 / MP5 / MP6 (Max 3)

Working MP1 / MP2 / MP3 / MP4 / MP5 / MP6 (Max 3)

Correct values: four or five correct values (1 mark)

Correct values: all six correct values (1 additional mark)

MP1 Correct outer loop iterating through entire array starting at second element

MP2 Temporary variables both initialised to current value of arrays

MP3 Insertion variable initialised

MP4 Correct inner loop criteria

MP5 Elements of both arrays inserted as appropriate / MP6 Insertion variable decremented / MP7 Temporary values replaced in correct place in arrays

MP1 Array size // Number of elements in the array

MP2 … time efficiency will improve if the number of elements to be sorted are fewer

MP3 Initial order

MP4 … if the array is partially sorted the insertion sort works better

O(n2) // O(N2)

(25) customer(betty).

(26) owns(large_tv, betty).

(27) wants(bluray_player, betty).

(Owner =) petrov, susan, sammy

MP1 device(D)

MP2 customer(A)

MP3 owns(D, A).

MP4 All logic conditions / punctuation correct (accept , for AND)